GRANULES OF OSTEOAPATITE AND GLASS-REINFORCED HYDROXYAPATITE IMPLANTED IN RABBIT TIBIAE

Granules of a modified hydroxyapatite, glass-reinforced hydroxyapatite composite and commercial hydroxyapatite were implanted in rabbit tibi ae. Histological studies were carried out after 1 and 2 months implant ation periods using light and fluorescence microscopy. A much higher p ercentage of bone contact was developed for both the glass-reinforced hydroxyapatite composite and the modified hydroxyapatite when compared to commercial hydroxyapatite (89-91% versus 66%) after 2 months impla ntation. The mechanism of bone formation and growth around implants is discussed in terms of the influence of elements incorporated into the se novel materials which are commonly found in bone tissues, such as N a, K and Mg, and the presence of a soluble beta-tricalcium phosphate p hase in the microstructure of the composite.